Gyroscopes are often used in navigation systems. For example, in inertial navigation systems, gyroscopes are used to determine the degree of rotation around a particular axis. The accuracy of gyroscopes, however, has been found to be affected by changes in age, temperature, shock, and other environmental factors. Therefore, frequent recalibration of the gyroscope or compensation methods may be necessary to maintain the desired accuracy of the navigation system over time.
Currently, navigation systems generally contain a singular gyroscope for cost, complexity, and other reasons. Performance of different gyroscopes varies over time depending on the operating conditions and brand of the gyroscope. Generally, higher quality gyroscopes that maintain high degrees of accuracy and precision over their lifecycle are more expensive than lower quality gyroscopes. Regardless of the brand of the gyroscope, recalibration of the gyroscope may be needed in order to compensate for inaccuracy in the gyroscope's readings to bring the gyroscope back into tolerance. Recalibration of gyroscopes is a costly endeavor as it requires the platform using the navigation system to be inoperable and generally requires the use of maintenance personnel.
When recalibration of a gyroscope is performed, the gyroscope is generally removed from the machine, positioned on a calibration assembly, and tested under a calibration procedure. In some instances, the gyroscope is transported to a laboratory or factory environment so that the gyroscope can be calibrated in a controlled environment. Alternatively, the gyroscope may be positioned on an in-field calibration tool. United States Patent Publication 2011/0066395 to Judd and titled Systems and Methods for Gyroscope Calibration discloses such a system in which a gyroscope can be removed from the machine and positioned on an in-field sensor platform having an accelerometer and a magnetometer. Judd states that the system determines a measured rotation based upon the rotation sensed by the gyroscope, derives a rotation based upon the changes in the earth's gravitational field sensed by the accelerometer, and derives a rotation based on changes in the earth's magnetic field sensed by the magnetometer, and then determines the compensation gain and compensation bias exhibited by the gyroscope based upon the actual rotation derived from the accelerometer and the magnetometer and the rotation measured by the gyroscope. However, there remains a need for alternatives to current calibration systems and methods, as they require human intervention and removal of the gyroscope, both of which lead to significant inefficiencies.